A method for determining a postural and visual behavior of a person

ABSTRACT

A method for determining a postural and visual behavior of a person, the method comprising:—a person image receiving step during which a plurality of images of the person are received,—a context determining step during which the plurality of images of the person are analyzed so as to determine context data representative of the context in which the person is on each image of the plurality of images,—an analyzing step during which the plurality of images of the person are analyzed so as to determine at least one oculomotor parameter of the person,—a postural and visual behavior determining step during which a postural and visual behavior of the person is determined based at least on the at least one oculomotor parameter and the context data.

FIELD OF THE INVENTION

The invention relates to a method for determining a postural and visualbehavior of a person, to an optical lens adapted for a person obtainedby the method of the invention, to a programmable optical lens whoseoptical function is adapted based on the optical function obtained by amethod of the invention, and to a computer program product comprisingone or more stored sequences of instructions corresponding to the methodof the invention.

BACKGROUND OF THE INVENTION

Usually, a person wishing to have an eyewear equipment goes to an eyecare practitioner.

The eye care practitioner orders the eyewear equipment at an optical labby sending an order request to the optical lab. The order requestcomprises person data, for example the person's prescription, spectacleframe data, for example the type of spectacle frame the person hasselected, and lens data, for example the type of optical lens the personhas selected.

The optical lab receives the order request and sends it to an opticallens designer software. The lens designer software uses some of the datacomprised in the order request to calculate the design of the opticallenses to be provided to the person. The optical design determined bythe lens designer software is sent to the optical lab and the opticallenses are manufactured based on the calculated design.

The manufactured optical lenses can be processed to add the opticaltreatments according to the order request.

The optical lenses are then sent to the eye care practitioner. Theoptical lenses may be edged to fit the spectacle frame prior to beingsent to the eye care practitioner and mounted on the spectacle frame.

The current optical lens delivering process presents some drawbacks.

In the recent years, new optical designs have been invented. These newoptical designs are more and more customized according to the person. Tocalculate such customized optical designs the lens designer needs moreand more data relative to the person. The wording “optical design”designates the set of parameters allowing defining a dioptric functionof an ophthalmic lens. Generally, the data relating to the person aremeasured or evaluated in very standard environment. Typically, the eyecare professional carries out a set of standard tests corresponding tothe average situation. For example, when determining far visionprescription, the eye care professional has the person under testrecognizing letters at a distance of about 5 meters.

When determining the near vision prescription, the eye care professionalmay have the wearer read a text at about 40 cm.

Usually, most of the vision tests are not customized.

An example, of a customizing of an optical function is considering therelative head and eye movements of the person when looking at blinkinglights to adapt the optical function to be provided as disclosed in thepatent application EP1834206.

The measurements of the relative movements of the head and eyes of theperson are usually carried out in a standard environment, for example aneye care professional lab.

As illustrated the determination of most of the wearer parameters aredone in very standard environment.

Recent developments in optical designs, allow a much greatercustomization of the optical functions to a point where customizing theconditions in which the parameters are determined may have an impact ofthe optical function.

Therefore, there is a need for a method for determining customizedparameters such as the postural and visual behavior of a person and thatis easy and quick to implement.

One object of the present invention is to provide such method.

SUMMARY OF THE INVENTION

To this end, the invention proposes a method for determining a posturaland visual behavior of a person, the method comprising:

a person image receiving step during which a plurality of images of theperson are received,

a context determining step during which the plurality of images of theperson are analyzed so as to determine context data representative ofthe context in which the person is on each image of the plurality ofimages,

an analyzing step during which the plurality of images of the person areanalyzed so as to determine at least one oculomotor parameter of theperson, and

a postural and visual behavior determining step during which a posturaland visual behavior of the person is determined based at least on the atleast one oculomotor parameter and the context data.

Advantageously, the method of the invention allows determining apostural and visual behavior based on oculomotor parameter of a persondetermined in relation with a context. Typically, the oculomotorparameters are determined in different visual environment or whilehaving the person carry out different or specific activities.

The images of the person may typically be images provided by the personitself and representative of the context in which the person is most ofthe time or for which the person wishes to have a specific opticalfunction.

For example, if the person likes to play chess outside, the imagereceived in the method of the invention may be images of said personplaying chess outside. Oculomotor parameters may be determined based onthe provided images and used to determine for a postural and visualbehavior of the person. Advantageously, the oculomotor parameters aredetermined in a “real-life” context allowing an accurate determinationof the postural and visual behavior. Furthermore, the method of theinvention allows comparing evolution of oculomotor parameters over timeif images corresponding to different time in the life of the person arereceived.

Additionally, the method of the invention allows determining a lensutilization anomaly such as an inappropriate utilization of opticallenses and/or utilization of optical lenses not adapted for the personbased on the postural and visual behavior.

Furthermore, the method of the invention allows determining an opticalfunction adapted for the wearer based on the postural and visualbehavior.

According to further embodiments which can be considered alone or incombination:

the method further comprises:

-   -   a reference postural and visual behavior data receiving step        during which reference postural and visual behavior data are        received, the reference postural and visual behavior data        corresponding to the appropriate postural and visual behavior of        a reference person wearing lenses of a specific prescription        adapted to said reference person, and    -   a comparison step during which reference postural and visual        behavior data and the postural and visual behavior of the person        are compared so as to determine a lens utilization anomaly, the        lens utilization anomaly referring to an inappropriate        utilization of the lenses and/or the utilization of lenses not        adapted for the person; and/or

the method further comprises

-   -   a prescription data receiving step during which prescription        data of the person are received, and    -   an optical function determining step during which an optical        function adapted for the wearer is determined based at least on        the prescription data and the postural and visual behavior of        the person; and/or

the optical function is adapted for the person in at least one context;and/or

during the optical function determining step a dioptric function adaptedfor the person is determined; and/or

during the optical function determining step an electrochromic functionadapted for the person is determined; and/or

plurality of images of the person received during the person imagereceiving step are received from at least one distant image data base;and/or

the plurality of images of the person received during the person imagereceiving step comprises at least part of the person's face, for exampleat least the person's eyes; and/or

the plurality of images of the person received during the person imagereceiving step comprise static images and/or videos of the person;and/or

the at least one oculomotor parameter relates at least to the gazingdirection of the person; and/or

the at least one oculomotor parameter relates at least to the gazingdistance of the person; and/or

the at least one oculomotor parameter relates at least to the positionand orientation of the head of the person; and/or

the context data relate to the activity carried out by the person on theimages; and/or

the context data relate to the visual environment of the person on theimages; and/or

the method further comprises:

-   -   prior to the context determining step a context data receiving        step during which context data representative of the at least        one context are received, and    -   further to the context determining step an image selection step        during which a plurality of images of the at least one person in        the at least one context are selected,    -   during the analyzing step the selected plurality of images of        the at least one person are analyzed; and/or

the method further comprising prior to the context determining andanalyzing steps an image selection step during which the images of theperson wearing single vision ophthalmic lenses or no ophthalmic lensesare selected and the context determining and analyzing steps are carriedout on the selected images; and/or

the method further comprises an optical function sending step duringwhich the optical function determined during the optical functiondetermining step is sent to a programmable lens device controllerarranged to control the optical function of a programmable lens; and/or

the method further comprises a manufacturing step during which anoptical lens having the optical function determined during the opticalfunction determining step is manufactured.

The invention also relates to a method of manufacturing an ophthalmiclens for a person, the method comprising:

an optical function determining step during which the optical functionof the ophthalmic lens is determined using a method according to theinvention, and

a manufacturing step during which the optical lens is manufactured.

The invention further relates to an optical lens adapted for a personobtained by the method according to the invention.

The invention further relates to a computer program product comprisingone or more stored sequences of instructions that are accessible to aprocessor and which, when executed by the processor, causes theprocessor to carry out at least the steps of the method according to theinvention.

The invention also relates to a computer-readable storage medium havinga program recorded thereon; where the program makes the computer executeat least the steps of the method of the invention.

The invention further relates to a device comprising a processor adaptedto store one or more sequence of instructions and to carry out at leaststeps of the method according to the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention will now be described, by way of exampleonly, and with reference to the following drawings in which:

FIG. 1 is a flow chart representing a method according to the invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

As illustrated on FIG. 1, the method for determining a postural andvisual behavior of a person according to the invention comprises:

a person image receiving step S1,

a context determining step S2,

an analyzing step S3,

a postural and visual behavior determining step S4.

During the person image receiving step S1 a plurality of images of theperson are received.

The images received during the person image receiving step may bereceived from a distant image data base.

For example, the method may comprise connecting to a distance image database, for example to a social network data base, to receive image of theperson.

Typically, the person allows access to images and/or videos of himavailable on at least one social network or personal data base.

The person may also provide the images via a storage medium, such as ahard drive, USB key, DVD, Blu-ray, or any known storage mean.

The images received during the image receiving step may comprise staticimages such as pictures and/or videos. The images may be 2-dimensionalimages or 3-dimensional images further comprising depth information.

So as to increase the accuracy of the method, preferably, at least partof the person's face is visible on the images provided during the imageproviding step. For example, at least the person's eyes are visible onthe images.

The method of the invention may further comprise a person data providingstep S10 during which person data related to the person are provided.The person data may comprise information concerning for example thetype, shape, dimension of spectacle frame the person has selected and/orthe person interpupillary distance and/or wearing condition parametersor any information concerning the person that may be useful fordetermining the postural and visual behavior of the person.

As illustrated on FIG. 1, the method of the invention may furthercomprise an image selection step S11. During the image selection stepS11, at least part of the images provided are selected.

For example, the images comprising at least part of the person's face,such as the person's eyes, are selected.

Images of the person wearing single vision ophthalmic lenses or noophthalmic lenses may be selected during the image selection step.

The image selection step may be based on information provided with theimages. For example, each image may comprise an indication of the dateon which the image was taken. Knowing the date on which the person hasstarted to wear progressive ophthalmic lenses, the image selection stepmay comprise selecting image based on their date, keeping only theimages prior to the date on which the person started wearing progressiveophthalmic lenses.

The image selection step may comprise image analyzing to identify theperson on the pictures.

For example, to check that at least part of the person's face is on theimages, the images are analyzed to detect faces on the image. Forexample, one may use the face detection method disclosed in U.S. Pat.No.6,697,502.

To check that the face detected in the one of the person one may use afacial recognition method, for example the method disclosed in W.Y.Zhao, R. Chellappa, Image-based Face Recognition: Issues and Methods,Image Recognition and Classification, Ed. B. Javidi, M. Dekker, 2002,pp. 375-402.

The method may comprise noise reduction for the image selected.

During the context determining step S2 the plurality of images of theperson are analyzed so as to determine context data representative ofthe context in which the person is on each image of the plurality ofimages.

The context determining step may comprise face recognition, inparticular if such face recognition is not part of the image selectionstep.

The context data may relate to the activity carried out by the person onthe images.

For example, the context data may identify directly an activity carriedout by the person or may be data allowing determining such activity, forexample an indication allowing determining the activity of the personfrom a data base and/or lookup table.

The person activity data may be provided directly by the person itself,for example by selecting an activity in a list of activities.

Furthermore, the person activity data may be determined based onanalysis of the images.

The activity that may be identified may be for example, but not limitedto driving, sport, playing golf, playing tennis, practicing archery,reading, walking, paragliding, etc. . .

Most researchers in HAR (Human Activity Recognition) use supervisedclassification algorithms. The algorithms are trained with labeledsamples to generate classification model. Then the model is used forclassification of input data. From the survey, the most popularalgorithms are Decision Trees, k-Nearest Neighbor, Naïve Bayes, SupportVector Machine and Neural Network.

An example a human activity recognition method is described in SULONG,GHAZALI, and AMMAR MOHAMMEDALI. “RECOGNITION OF HUMAN ACTIVITIES FROMSTILL IMAGE USING NOVEL CLASSIFIER.” Journal of Theoretical & AppliedInformation Technology 71.1 (2015).

The context data may relate to the visual environment of the person onthe images.

For example, the context data may relate to any parameter of theenvironment of the person on the images that may have an impact on thevisual behavior of the person.

For example, the context data may relate to spectral features andintensity of the light received by the person on the images.

Furthermore, the context data may relate to temperature and/or humidityof the environment of the person, the amount and/or the type ofallergens and/or pollutants contained in the environment of the personand/or an indication of the localization of the person such as indoor oroutdoor and/or the place of carrying out the activity of the person,proximity to relief and/or water, etc . . .

During the analyzing step S3 the plurality of images are analyzed so asto determine at least one oculomotor parameter of the person.

The oculomotor parameters of the person may comprise as eye movementsfor example gaze lowering, and/or saccades for example head-eyecoordination, and/or convergence and/or opening of the eyelid and/orpupil diameter and/or blink frequency and/or duration of the blinkand/or strength of the blink and/or the position and/or orientation ofthe head of the person, for example reading distance.

The data collected during the analyzing step can be post treated todetermine further information such as the dominant eye of the person oridentify the area of the optical lens that is the most used by theperson depending on the type of activity of the person and/or theenvironment of the person.

For example, for each image, the distance to the point observed by theperson is evaluated, and then its proximity is determined. If theactivity is far distance vision in this case proximity is set to beequal to 0.

To calculate a distance between two objects on a 2D image for which thecontext is known, the depth is taken into account.

Typically, to determine the distance between two elements on a 2dimension image, such as an eye and an object, one performs a contoursearch to detect the contour of the two elements, then an Euclideanmeasurement between the barycenter's of the form of the two element isperformed.

In order to calculate a distance that takes into account the depth ofthe image, a method may be used to obtain the 3D information and toconvert the Euclidean distance. An example of such a method is disclosedin “From 2D TO 3D Through Modelling Based On A Single Image” by D.Gonzalez-Aguilera, The Photogrammetric Record 23(122): 208-227 (June2008).

The method for determining distance may require knowing the size ofelement present in the image. For example, if both eyes of the personare present on the image and the interpupillary distance of the personis known it may be used as a reference element.

Any element of known size, such as a credit card, a spectacle frame, asmartphone present in the image may be used as reference element forcalculating distance.

Therefore, the method of the invention may further comprise identifyingan element of known dimension in the images provided.

In addition to the gazing distance, the head angles of the person andthe direction of gaze may be evaluated in the images.

For example, the person's posture may be determined using the methoddisclosed in US20070268295, the head angles may be deduced therefrom.

The gazing direction may be determined using the method disclosed inGaze direction estimation from static images; Krystian Radlak; MichalKawulok; Bogdan Smolka; Natalia Radlak; Multimedia Signal Processing(MMSP), 2014 IEEE 16th International Workshop.

During the postural and visual behavior determining step S4, a posturaland visual behavior of the person is determined based at least on the atleast one oculomotor parameter and the context data.

As illustrated on FIG. 1, the method of the invention may furthercomprises a reference postural and visual behavior data receiving stepS5 during which reference postural and visual behavior data arereceived. The reference postural and visual behavior correspond to theappropriate postural and visual behavior of a person wearing opticallenses of a specific prescription adapted to said reference person.

The reference postural and visual behavior may correspond to theappropriate postural and visual behavior of a person carrying out aspecific activity and wearing optical lenses of a specific prescriptionadapted for said specific activity.

During the comparison step S6 the reference postural and visual behaviordata and the postural and visual behavior of the person are compared soas to determine an optical lens utilization anomaly.

The lens utilization anomaly refers to an inappropriate utilization ofoptical lenses and/or to the utilization of optical lenses not adaptedfor the person.

As illustrated on FIG. 1, the method of the invention may furthercomprises a prescription data receiving step S7.

During the prescription data receiving step prescription data relatingto the prescription of the person are received.

The prescription of the person is a set of optical characteristics ofoptical power, of astigmatism and, where relevant, of addition,determined by an ophthalmologist in order to correct the vision defectsof the person, for example by means of a lens positioned in front of itseye. For example, the prescription for a progressive addition lenscomprises values of optical power and of astigmatism (modulus and axis)at the distance-vision point and, where appropriate, an addition value.

For example, the prescription of the person may be the prescription ofan emmetropic person.

During the optical function determining step S8 an optical functionadapted for the person is determined based at least on the prescriptiondata and the postural and visual behavior of the person.

The optical function determination may comprise selecting the mostappropriate optical function in a predefined list of optical function.

The selected optical function may then be customized based on theprescription data, the at least one oculomotor parameter and the contextdata.

According to an embodiment of the invention, the optical function may bedetermined using optimization algorithms based on the prescription dataand the postural and visual behavior of the person.

In the sense of the invention, the optical function corresponds to afunction providing for each gaze direction the effect of the opticallens on the light ray passing through the optical lens.

The optical function may comprise dioptric function, electrochromaticfunction, light absorption, polarizing capability, reinforcement ofcontrast capacity, etc . . .

The dioptric function corresponds to the optical lens power (mean power,astigmatism etc . . . ) as a function of the gaze direction. Thedioptric function may be optimized using the method according to theinvention.

For example, if the ophthalmic lens to be provided to the person is aprogressive addition lens the method according to the invention may beused to optimize various parameters of the optical function among whichthe relative positions of the near and far vision zones and/or the typeof design and/or the length of progression and/or the size of theprogressive corridor and/or the widths of the different vision zones.

In the sense of the invention a progressive addition lens is anophthalmic lens having a far vision zone, a near vision zone, and aprogressive corridor (or channel) there between. The progressivecorridor provides a gradual power progression from the far vision zoneto the near vision zone without dividing line or prismatic jump.

In the sense of the invention the length of progression of a progressiveaddition lens corresponds to the distance measured vertically (in wornconditions) over the lens surface between the fitting cross and a pointon the meridian line at which the mean sphere has a difference of 85%relative to the mean sphere at the far vision point.

The wording “optical design” is a widely used wording known from the manskilled in the art in ophthalmic domain to designate the set ofparameters allowing defining a dioptric function of an ophthalmic lens;each ophthalmic lens designer has its own designs, particularly forprogressive ophthalmic lenses. As for an example, a progressiveophthalmic lens “design” results of an optimization of a progressivesurface so as to restore a presbyope's ability to see clearly at alldistances but also to optimally respect all physiological visualfunctions such as foveal vision, extra-foveal vision, binocular visionand to minimize unwanted astigmatisms. For example, a progressive lensdesign comprises:

a power profile along the main gaze directions (meridian line) used bythe lens wearer during day life activities,

distributions of powers (mean power, astigmatism, . . . ) on the sidesof the lens, that is to say away from the main gaze direction.

These optical characteristics are part of the “designs” defined andcalculated by ophthalmic lens designers and that are provided with theprogressive lenses. For example, it is possible to detect if the personis in a category of eye mover or a category of head mover, or anyintermediate category, by measuring the range of gazing direction of theeyes (horizontal or vertical).

Then, if the person is of a category of eye mover, a progressive harddesign is proposed, whereas if the wearer is head mover, a soft designis proposed, whereas a tradeoff between hard/soft designs is to beproposed for intermediate category.

The category can be determined based on the minimum/maximum or thevariance of the gaze direction.

The size of the area of an optical lens to be provided to the person mayalso be optimized with the method according to the invention. Indeed,the method according to the invention can provide information on thesize of the area of an optical lens used by the person. Each person mayuse area of different size, therefore the size of the optical lens maybe adjusted to correspond to the needs of the person.

The optimization of the optical lens may consist in optimizing theposition of the optical lens in the spectacle frame. In particular theposition of a reference point of the optical lens, such as the prismreference point, relative to the eye of the person may be optimized by amethod according to the invention.

For example, it is possible to determine in different context the gazedirection for far vision, take the average gaze direction, determine theimpact of this average gaze direction with the frame shape and thenposition the fitting cross of a progressive lens at this location.

According to an embodiment of the invention the transmission function ofthe optical lens can be optimized. In the sense of the invention thetransmission function corresponds to a function providing for each gazedirection the average transmission over a range of wavelength. Theaverage transmission over a range of wavelength corresponds to thepercentage of intensity of the incident light within the correspondingrange of wavelength that is transmitted through the optical system.

For example, the context data may be used to propose differenttransmission function, for example category between 0-4 (ISO8980-3)adapted to the person's environment, or to propose specific UV cut-offsolution, for example Crizal UV AR coatings, or polarized lenses.

According to an embodiment of the invention, the optical functiondetermining step can take the form of a prescription of specific typesof lenses to the person. For example, if the analyzing step showsfrequent watering of the eye to reddish glow revealing visual fatigue,lens reducing visual strength can be proposed to the person. An exampleof lens is Essilor antifatigue™.

According to an embodiment of the invention, the method according to theinvention can be used to optimize classic optical lenses that aremanufactured and edged to fit in a spectacle frame, for example the sametype of spectacle frame as the person is wearing on the images.

According to an embodiment of the invention, the optical function isadapted for the person in at least one context.

As illustrated on FIG. 1, the method may further comprise prior to thecontext determining step a context data receiving step S20.

During the context data receiving step S20, context data representativeof the at least one context, for example corresponding to a choice ofthe person, are received.

During a second image selection step S21, the images corresponding tothe context data are selected. The plurality of images of the at leastone person in the at least one context are analyzed during the analyzingstep.

Advantageously, the optical function is optimized to a specific contextfor example for a specific activity and/or a specific visualenvironment.

The invention also relates to a method of manufacturing an ophthalmiclens for a person, the method comprising:

-   an optical function determining step during which the optical    function of the ophthalmic lens is determined using a method    according to the invention, and-   a manufacturing step S14 during which the optical lens is    manufactured.

The invention also relates to the optical lens adapted for a personobtained by the method of the invention.

Alternatively, the optimization method according to the invention can beused to optimize the optical function of an adjustable lens, for examplea programmable lens.

Therefore, the method of the invention may further comprise an opticalfunction sending step S12 during which the optical function determinedduring the optical function determining step is sent to a programmablelens device controller arranged to control the optical function of aprogrammable lens.

The invention has been described above with the aid of embodimentswithout limitation of the general inventive concept; in particular themounted sensing device is not limited to a head mounted device.

Many further modifications and variations will suggest themselves tothose skilled in the art upon making reference to the foregoingillustrative embodiments, which are given by way of example only andwhich are not intended to limit the scope of the invention, that beingdetermined solely by the appended claims.

In the claims, the word “comprising” does not exclude other elements orsteps, and the indefinite article “a” or “an” does not exclude aplurality. The mere fact that different features are recited in mutuallydifferent dependent claims does not indicate that a combination of thesefeatures cannot be advantageously used. Any reference signs in theclaims should not be construed as limiting the scope of the invention.

1. A method for determining a visual and postural behavior a person, themethod comprising: a person image receiving step S1 during which aplurality of images of the person are received, a context determiningstep S2 during which the plurality of images of the person are analyzedso as to determine context data representative of the context in whichthe person is on each image of the plurality of images, an analyzingstep S3 during which the plurality of images of the person are analyzedso as to determine at least one oculomotor parameter of the person, anda postural and visual behavior determining step S4 during which theoptical and postural behavior of the person is determined based at leaston the at least one oculomotor parameter and the context data.
 2. Themethod according to claim 1, further comprising: a reference posturaland visual behavior data receiving step S5 during which referencepostural and visual behavior data are received, the reference posturaland visual behavior data corresponding to the appropriate postural andvisual behavior of a reference person wearing lenses of a specificprescription adapted to said reference person, and a comparison step S6during which reference postural and visual behavior data and thepostural and visual behavior of the person are compared so as todetermine a lens utilization anomaly, the lens utilization anomalyreferring to an inappropriate utilization of the lenses and/or theutilization of lenses not adapted for the person.
 3. The methodaccording to claim 1, further comprising: a prescription data receivingstep S7 during which prescription data of the person are received, andan optical function determining step S8 during which an optical functionadapted for the wearer is determined based at least on the prescriptiondata and the postural and visual behavior of the person.
 4. The methodaccording to claim 1, wherein the optical function is adapted for theperson in at least one context.
 5. The method according to claim 3,wherein during the optical function determining step a dioptric functionadapted for the person is determined.
 6. The method according to claim3, wherein during the optical function determining step anelectrochromic function adapted for the person is determined.
 7. Themethod according to claim 1, wherein the plurality of images of theperson received during the person image receiving step are received fromat least one distant image data base.
 8. The method according to claim1, wherein the plurality of images of the person received during theperson image receiving step comprises at least part of the person'sface, for example at least the person's eyes.
 9. The method according toclaim 1, wherein the plurality of images of the person received duringthe person image receiving step comprise static images and/or videos ofthe person.
 10. The method according to claim 1, wherein the at leastone oculomotor parameter relates at least to the gazing direction of theperson.
 11. The method according to claim 1, wherein the at least oneoculomotor parameter relates at least to the gazing distance of theperson.
 12. The method according to claim 1, wherein the at least oneoculomotor parameter relates at least to the position and orientation ofthe head of the person.
 13. The method according to claim 1, wherein thecontext data relate to the activity carried out by the person on theimages.
 14. The method according to claim 1, wherein the context datarelate to the visual environment of the person on the images.
 15. Themethod according to claim 1, further comprising: prior to the contextdetermining step a context data receiving step S20 during which contextdata representative of the at least one context are received, andfurther to the context determining step an image selection step S21during which a plurality of images of the at least one person in the atleast one context are selected, wherein during the analyzing step theselected plurality of images of the at least one person are analyzed.16. The method according to claim 1, further comprising: prior to thecontext determining and analyzing steps an image selection step S 11during which the images of the person wearing single vision ophthalmiclenses or no ophthalmic lenses are selected, wherein the contextdetermining and analyzing steps are carried out on the selected images.17. An optical lens adapted for a person having an optical functiondetermined by the method according to claims
 3. 18. A non-transitorycomputer program product comprising one or more stored sequences ofinstructions that are accessible to a processor and which, when executedby the processor, causes the processor to carry out the steps of themethod according to claim
 1. 19. (canceled)